Cutting machine



E. H. COMPTON CUTTING MACHINE Aug. 2l, 1951 5 Sheets-Sheet 1 Filed DeC. 4, 1947 Edward H. Compton Aug. 21, 1951 E. H. COMPTON 2,565,169

CUTTING MACHINE Filed DecY 4, 1947 1 5 Sheets-Sheet 2 l will* LJJ Edward H. Compton INVENTOR.

Allg 21, 1951 E. H. COMPTON 2,565,169

CUTTING MACHINE Filed Dec. 4, 1947 5 Sheets-Sheet 3 Edward H. Compran 1i md5/wey @mm Aug. 21, 1951 E. H. COMPTON 2,565,169

CUTTING MACHINE Filed Deo. 4, 1947 5 sheets-sheet 4 Attorne Patented Aug. 2l, 1951 ICUTTING MACHINE Edward H. Compton, Akron, Ohio, assignor of one-half to Le Roi Oswald, Akron, Ohio Application December 4, 1947, Serial No. 789,736

8 Claims. (Cl. 164-86) This invention relates to a machine for cutting, from the inflatable core of a tire curing mold, a section containing the casing of the inflation valve of said core.

Casings of pneumatic vehicle tires are cured -in a mold while expanded into contact with the latter by means of an inflatable rubber core. The mold core is provided with an inflation valve Whose metallic .casing is bonded in the core, and since the metal and rubber have diierent coeiiicients of expansion, the adhesion of the core to the valve casing is soon weakened and repair is required. At the present time, a large irregular section containing the valve section is cut by means of a knife from the core by hand, a slow laborious task requiring frequent lubrication of the knife. A molded rubber plug havingv a valve casing bonded therein is then inserted in the irregular hole thus made in the core, and, due to the non-uniform shapes and sizes of the holes thus made, large and different quantities of uncured rubber are used to fill the spaces between the walls of the holes and the inserted plugs before vulcanizing the latter in place. As a result of this, the plugs are not effectively bonded in place, so that the cores soon require further repair or must be discarded as unt for` further use.

The primary object of the present invention, therefore, is to provide an eiiicient machine for rapidly cutting, from the inflatable rubber core of a tire curing mold, a uniform substantially cylindrical section of predetermined size and containing the casing of the inflation valve of the core, whereby a cylindrical rubber replacement plug of a standard predetermined size,- and having a valve casing bonded therein, may be fitted in the hole left in the core by removal of the section out therefrom, and whereby such standard plug may be effectively vulcanized to the core without the use of a great quantity of rubber to ll the space between the wall of the hole and the inserted replacement plug.

Another object is to provide means connectible tothe valve casing of the core for placing l the adjacent portion of the core under tension, so that the cutter may more easily perform its cutting action in severing the section from the core.

A further object is to provide an improved rotary cutter for severing the section from the core, said cutter having four equally spaced blade carrying arms arranged in box formation and to the outer faces of which successive blades are secured in right angular relation and parallel with the axis of rotation of the cutter, whereby, when the cutter is in operation, the cut is repeatedly re-opened and successive cuts are made at uniform intervals of time. Thus, the core material is repatedly flexed by the cutter so as to permit air to flow past the blades and dissipate heat generated by the cutting operation. A result of this is that the cuttings produced by the cutter are dry and granular, instead of being tacky and acting to seize and chip or break the blades.

Other objects are to provide improved means for mounting and vertically adjusting the cutter to adapt the machine for operation upon mold cores of diiierent cross-sectional sizes; to provide novel means for moving the cutter downwardly to feed it to the work; and to provide a machine of the kind described involving a relatively simple and practical combination and arrangement of organized elements which provides for ready operation and control of the machine by a person standing in front of the machine and the work being operated upon.

The exact nature of the present invention, as well as still further objects and features 'thereof, will become apparent from the following description when considered in connection with the accompanying drawings, in which:

Figure 1 is a front perspective view, partly broken away, showing a cutting machine constructed in accordance with the present invention and illustrating the condition of the machine after it has been used to cut a section from a mold core.

Figure 2 is an enlarged fragmentary view of the upper portion of the machine shown in Figure 1, partly in side elevation and partly in section.

Figure 3 is a view somewhat similar to Figure 2, looking at the opposite side of the machine and with the cutting unit lowered and the stem of the core tensioning means elevated.

Figure 4 is a fragmentary top plan view of the construction as shown in Figure 3.

Figure 5 is a section taken on line 5 5 of Figure 3, with parts omitted.

Figure 6 is a section taken substantially on line 6 6 of Figure 3, with parts omitted.

Figure 7 is a View mainly taken on line 1-1 of Figure 4, but with parts broken away and in section and omitted.

Figure 8 is a vertical section taken substantially on line 8-8 of Figure 2, but with the stem of the core tensioning means coupled to the casing of the inflation valve of a mold core.

Figure 9 is an enlarged elevational view of the cutter.

Figure 10 is a horizontal section taken on line IB-I of Figure 9.

Figure 11 is a fragmentary sectional detail taken on line II-Il of Figure 4.

Figure 12 is an exploded sectional view of the coupling means for connecting the stem of the tensioning means with the valve casing of the mold core.

Figure 13 is a horizontal sectional view taken through the upper portion of the cutter and an adjacent portion of the mold core from which a section containing the inflation valve ycasing is being cut by the cutter.

Figure 14 is a view similar to Figure lf3 taken through the cutter at a lower point.

Referring in detail to the drawings, the illustrated embodiment of the invention comprises a base plate 5 adapted to be suitably flatly fixed on the top of a bench or the like and having a central hub 5 inwhich is fitted the lower end of an upright post 1, the post Vbeing secured in 4hub 6 7,by means of `a set screw 9 carried Iby said hub and engaged in a peripheral annular groove 9 provided inthe lower end of post 1. The post 1 has a longitudinal groove It in its upper portion, within which is Vsecured Aa rack bar 'l I. Slidably tted on the post 1 is a lsleeve I2 provided at one yside of Vits upper end with spaced bearing brackets I3 and I4 in vwhich Yis journalled the rear end of a horizontal shat I5 having -a handwheel I6 secured on its front end. Journalled on Vthe sha-ft I5 between the brackets i3 and I4 is a Spur gear I1 which meshes `with rack `bar I I, and

secured on said shaft I5 rearwardly of bracket I4 is a pinion I8. An axle I9 ,is supported by the brackets -I 3 and I4, and a spur gear 29 and a pinion `2I, which are clutched together at 22, are journalled on said axle and respectively meshed with the pinion I8 -and gear I1. The pinions I8 and 2| and gear 20 provide a reduction gearing between shaft I 5 and gear l1, through which `rotation of said shaft will cause vertical adjustment of sleeve I2 on post 1. Rigid with and projecting lfrom opposite sides of the upper end rof sleeve I2 is a forwardly projecting relatively long arm 2'3 and a short rearwardly projecting arm 24. The shaft I5 is disposed above and to one side of, as well as parallel with, -arm 23, and projects forwardly of the latter. A short post is carried by ,arm 23 near the forward end of the latter, and a split resilient brake band 25 is Xed on lthe upper end of this post. The :brake band is normally expanded or released from a brake drum 21 secured on shaft I5, and a clamping screw 28 is provided to contract said brake band into engagement with said drum to hold the shaft I5 from turning and thereby secure the sleeve I2 in any of its vertically adjusted positions. A vertical stem 29 has its upper end slidably keyed in and extended through the forward end of arm 23, and this stem is urged downwardly by a compression spring 30 placed thereon between the arm 23 and an abutment collar 3i secured on stem 29 below the arm 23. A fragment of an inatable core for a tire curing mold is shown at C, and it has the usual casing 32 of an inflation valve bonded therein as usual. Means is provided to detachably connect the lower end of stern 29 to the valve casing 32 so that the portion of the core adjacent said valve casing may be pulled upwardly and placed under tension during the operation of cutting a section 33 from the core C which contains the valve casing 32. This means includes a cross pin 34 in the lower end of stem 29, a hollow coupling member 35 having a stem 35 adapted to be threaded into the valve casing 32, a coupling cap 31 adapted to be threaded on the body 38 of coupling member 35, and a spring in the coupling member 35, the body 33 having opposed open longitudinal slots 4D, and the cap 31 having opposed bayonet slots 4I to receive the ends of cross pin 34 when the slots 4l) are registered with the open vertical ends of slots 4I.

Thus, by turning the cap 31 to move the vertical ends of slots 4I out of register with slots 49, parts of the cap will be moved over the ends or" the cross pin 34 to connect the stem to the coupling elements. When the stem 29 enters the coupling member 35, it contacts and compresses spring 39 so that play between the ends of cross -pin .34 and coupling cap 31 is opposed by said spring 39.

An elongated longitudinal slot 42 is provided in the upper end of stem 29 as shown more clearly in VFigure 8, and pivoted .near one end on a horizontal pin 43 to the upper end of and within the slot 42 of stem '29 is a latch plate 44. The latch plate 44 has side weights 45 on its free end, and a thumb-piece 45 on its pivoted end. 'When the stem .29 is raised, the latch plate 44 is ythrown off-center and gravitates to the position shown in Figure 3, where it rests on arm Y23. By swinging the latch plate, it may be used to regulate the travel of stem 29. The stem 29 is raised in cutting position kby means of a lever 41 pivotally mounted at 43 on a bracket 4S' carried by arm 23, for vertical swinging movement. The lever 41 has an operating Vhandle 49 which extends forwardly and downwardly as well as laterally, and said lever is provided with a forked free end which straddles the stem '29 and which is indicated at 49. When lthe lever 41 kis swung upwardly, its forked end Yengages the projecting ends of pin .43 to raise the stern 29 and permit the latch plate 44 to lower. By pressing on the thumb-piece 45, the latch plate 44 may be released so as to allow spring 30 to move the stem 2,9 downwardly.

Slidably fitted on the lower portion. of sleeve IZ is a shorter sleeve 50, on one side of which is clamped, by U-bolts 5i, an adjustable mounting bracket 52 for a vertically disposed electric motor 53. A long horizontal arm 54 is fixed to the opposite side of sleeve 59 and extends parallel with and beneath the arm 23. Tension springs v55 provide elastic connections between the inner ends of arms 23 and 54. The arm 54, bracket 52, motor 53 and sleeve 59 form parts of a motor driven cutting unit slidable on post 1 and suspended from the vertically adjustable supporting unit 23, I2, 24., etc., by the springs 55. The arm A54 Ais of I-beam fform and has an upwardly oiset forward end portion 56 whose web is provided with an elongated central slot 51, and whose forward terminals are formed with vertically aligned bosses 5B having a tubular spindle 59 journalled therein and retained in place by a nut 9E. A thrust bearing 3| is provided between the lower boss 58 and a ange 52 provided on the lower portion of Spindle 59, and a/large pulley G3 is secured on Ythe spindle 59 and disposed within slot 51. Intermediate its ends, the arm 54 has the lower end of a vertical spindle 54 xed thereto, and journalled on this spindle is a hub 35 provided with reduced ends on which are secured a large pulley 66 and a small pulley 61. The pulley 63 is aligned with pulley 31 and operatively connected therewith by an endless driving belt 68.

The drive shaft of motor' 53 has a small pulley! 69 secured thereon in linewith pulley 66, and a driving belt 1|] passes around these pulleys 69 and! 66 to complete a reductionvdriving connection between the motor and spindle 59. Secured on the lower end of spindle 59 is a cutter including a head 'H having four equally spaced parallel prongs 12 arranged in box formation about and parallel with the axis of rotation of the cutter, and blades T3 secured tothe outer faces of said prongs so that successive blades are disposed in i right angular relation. The lower portions 12 of the prongs 'l2 are inwardly tapered to provide clearance for cuttings. The stem 29 slidably extends through the spindle 59 into head 1I, andmaintains alignment of arms 23 and 54. When the motor driven cutting unitI is raised and the stem 29 is lowered as in Figures 1 and 2, the lower end of stem 29 projects below the cutter to permit ready connection of stem 29 to or disconnection of the same from the valve casing 32, respectively before and after cutting section 33 from the core C. As shown in Figures 2, 3 and 8, the upper portion 'M of the bore of spindle 59 is of suicient diameter to receive thespring 30 and abutment collar 3l when the motor driven cutting unit is raised.

Means is provided for manually forcing the cutting unit downwardly to feed the cutter to the work. This means includes vertical bellcrank levers 'l5 and 16 respectively pivoted on the front portion of arm 23 and on the arm 24, a link 11 connecting one arm of lever 15 to one arm of lever T5, links 13 connecting the other arms of levers 15 and 16 to the cutting unit, and a handle 19 fixed to and extending vforwardly from the lever 15. By rocking the lever l5 forwardly, the links 18 are caused to move down and to force the cutting unit down so as to feed the cutter to the work disposed on the bench beneath said cutter as shown in Figures 1 and 8. The vertical adjustment of the supporting unit by operation of shaft I5 is required to properly set the cutting unit at different heights in accordance with the different cross-sectional sizes of different mold cores. It is noted that the weight of parts dis-- posed at one side of post 'I is substantially counterbalanced by the weight of the motor 53 disposed at the opposite side of said post.

The machine is operated in a manner somewhat similar to a drill press. The mold core is placed upright on the bench with its inflation valve casing directly under the cutter, the cutting unit being in the raised position of Figures 1, 2 and 8. The lower end of stem 29 is then coupled to the air valve casing, and the stem 29 is raised to place the portion of the mold core adjacnt the inflation valve casing under vertical tension. Handle 'i9 is then manipulated to feed the cutter downwardly to the work, the motor 53 having previously been placed into operation for driving the cutter. Also, the height of the supporting unit will have been previously adjusted in accordance with the size of the mold core being operated upon, such adjustment being eected by actuation of shaft l5 upon release of brake band 25. The adjustment is, of course, secured by tightening the band 29 before the cutting operation is actually started. The weight of the cutting unit is taken by the springs 55, so that the pressure actually required for feeding the cutting unit downwardly is only that necessary to press the knives into the rubber. .As soon as the section 33 is completely severed from the mold core, the cutting unit is raised so that the lower end of stem 29 is exposed therebeneath. The section 33 may then be readily uncoupled from the stem 29 so that it may be removed preparatory to placing a standard replacement plug in the hole left by removal of the section 33.

I am aware that various hand tools or plug cutters have been devised to remove valves lfrom air bags and the like, while the rubber of the latter is in compression. Use of such tools or cutters require exerting pressures thereon ranging from fifty to two hundred pounds per foot. In performing a cutting operation in this old way and by such old means, the rubber is placed under compression, and considerable heat is generated by friction. As a result of this, much power is required and the rubber becomes tacky so as to grip the cutter and even cause stalling or breaking thereof. By the use of the present cutter and means for placing the rubber under tension during the cutting operation, these objections are overcome. The cutter repeatedly stretches and releases the rubber and provides separated spaces through which air may flow past the blades to dissipate any heat generated. In practice, use of the present machine has been found to produce cuttings which are dry and granular, and the blades have been found to only heat to a relatively slight extent even though no lubricant is used on the blades. The cutting operation is per-formed easily and speedily, and a uniform hole is left by removal of the section of the core, so that standard sized replacement plugs can be employed in repairing the mold core, effectively.

From the foregoing description, it is believed that the construction, operation and advantages of the present invention will be readily understood and appreciated by those skilled in the art. Modincations and changes in details of construction are contemplated, such as fairly fall within the spirit and scope of the invention as claimed.

Having described the invention, what is claimed as new is:

l. A machine for cutting, from the inflatable core of a tire-curing mold, a section containing the casing of the inflation valve of said core, comprising a supporting unit including a stationary member, a vertically movable cutting unit disposed beneath said stationary member of the supporting unit and including a supporting member carrying a rotary cutter rotatable on a vertical axis and a driving motor for said cutter, yieldable means suspending the cutter unit from said stationary member of the supporting unit, manually operable means operating between said stationary member and said supporting member to force the cutting unit downwardly to feed the cutter to work disposed therebeneath, a stem movable axially through the cutter and having means to connect the same with the inflation valve casing, and means to raise said stem for placing the portion of the mold core adjacent to said inflation valve casing under tension.

2. The construction defined in claim 1 together with a spring urging said stem downwardly, said stem being vertically slidable through said stationary member of the supporting unit, and means for regulating the travel of said stem.

3. The combination of claim 2 and said means for regulating the travel of said stem comprising a vertical latch plate pivoted off-center to the upper end of said stem and coacting with said stationary member.

' 4. The combination of claim 3 and said latch plate being weighted to gravitate to a position for holding the stem in an upward position when the latter is raised, and means for raising said stem.

5. In a machine of the character described, a motor driven cutter mounted for rotation on a vertical axis and comprising a head having four equally spaced parallel depending prongs arranged in box formation about and parallel with the axis of rotation of the cutter, and blades eX- tending below and being secured to the outer faces of said prongs so that successive `blades are disposed in right angular relation` 6. In a machine for cutting apertures in rubber, a rotatably driven cutter, means for forcing said cutter axially through a body of rubber, said cutter comprising a rotatable head having a plurality of spaced axial projections, a plurality of cutting blades secured to said projections and having side and terminal cutting edges, portions of said projections having a radius greater than the radius of the side cutting edges of the blades with respect to the axis of the cutter head to maintain the rubber surrounding the aperture formed by said cutting blades under tension as the cutting blades are rotated and forced through the rubber.

7. In a machine for cutting apertures in rubber, arotatably driven cutter, means for forcing said cutter through a body of rubber, said cutter comprising a rotatable head, a plurality of cutting blades secured to said head and having side and terminal cutting edges, portions of said head havu ing a radius greater than the radius of the side cutting edges of the blades with respect to the axis of the cutter head to maintain the rubber surrounding the aperture formed by said cutting blades under tension as the cutting blades are rotated and forced through the rubber.

8. In a machine for cutting apertures in rubber,

a rotatably driven cutter, means for forcing said cutter through a body of rubber, said cutter comprising a rotatable head, a plurality of cutting blades secured to said head and having side and terminal cutting edges, portions of the head between adjacent cutting blades having a radius greater than the radius of the side cutting edges of the blades with respect to the axis of the cutter head to maintain the rubber surrounding the aperture formed by said cutting blades under tension as the cutting blades are rotated and forced through the rubber.

EDWARD H. COMPTON.

REFERENCES CITED The following references are of record in the 111e of this patent:

UNITED STATES PATENTS Number Name Date 1,046,394 Kolassa Dec. 3, 1912 1,622,256 Stevens Mar. 22, 1927 1,731,010 Krause Oct. 8, 1929 1,768,328 Nichols June 24, 1930 1,781,274 De Roo Nov. 11, 1930 1,876,775 Smith Sept. 13, 1932 2,067,456 Meisel Jan. 12, 1937 2,121,957 Fleischli June 28, 1938 2,167,279 Manny July 25, 1939 2,272,895 Stevens Feb. 10, 1942 2,356,046 Garlick Aug. 15, 1944 2,426,275 Krebs Aug. 26, 1947 2,440,213 Spring Aug. 20, 1948 FOREIGN PATENTS Number Country Date 410,412 Great Britain May 17, 1934 

